The present invention relates to a fine processing method, and more specifically relates to a fine processing method for producing semiconductor devices.
In order to produce semiconductor devices, such as MESFETs and HEMTs, used in the microwave frequency range, it is required to form, for example in a gate forming process, fine grooves of 0.5 .mu.m or less in width on a substrate, and therefore to form a resist pattern having fine lines of 0.5 .mu.m or less in width. Usual photo-exposure methods cannot provide such a fine resist pattern due to the limitation originating from the minimum wavelength of exposure light.
Therefore, electron beam exposure methods, focused ion beam methods, etc. have conventionally been employed to form such fine resist patterns. However, these methods have a disadvantage of very long exposure time, resulting in low productivity.